Epineural Neurorrhaphy of a Large Nerve Defect Due to IatroGenic Sciatic Nerve Injury in a Maltese Dog

SIMPLE SUMMARY: Sciatic nerve injury could occur due to mistake of surgery and called as ‘iatrogenic injury’. This type of injury is rare in dogs. Historically, this injury is treated through physiotherapy. However, if the nerve is completely transected, surgery such as nerve repair could be addressed. Unfortunately, if there is a large gap between transected sciatic nerve, it is very difficult to treat. Sometimes amputation is recommended because of permanent problem with dog’s hind leg. By the way, it is not known how long the gap can be treated in dogs before the important decision of whether to amputate the leg or not. Therefore, we would like to described a good result of treating an iatrogenic sciatic nerve injury with a large defect measuring 20 mm in length in a small Maltese dog. The dog suffered nerve injury after hip joint surgery and could not be walking himself for 2 months. So, we decided to treat him by nerve repair despite of large gap. Sensation and walking function of his hind leg was recovered almost completely after 2.5 years. Although sciatic nerve injury with large gap is a concern, it could be treated through surgery, even in small Maltese. ABSTRACT: Epineural neurorrhaphy is a standard nerve repair method, but it is rarely reported in veterinary literature. Epineural neurorrhaphy in canine sciatic nerve injury are described in this report. An 11-month-old, castrated male Maltese dog, presented with an one-month history of non-weight bearing lameness and knuckling of the right pelvic limb. The dog showed absence of superficial and deep pain perception on the dorsal and lateral surfaces below the stifle joint. The dog had undergone femoral head and neck osteotomy in the right pelvic limb one month prior to referral at a local hospital. Based on physical and neurological examinations, peripheral nerve injury of the right pelvic limb was suspected. Radiography showed irregular bony proliferation around the excised femoral neck. Magnetic resonance imaging revealed sciatic nerve injury with inconspicuous continuity at the greater trochanter level. A sciatic nerve neurotmesis was suspected and surgical repair was decided. During surgery, non-viable tissue of the sciatic nerve was debrided, and epineural neurorrhaphy was performed to bridge a large, 20-mm defect. The superficial and deep pain perception was progressively improved and restored at 3 weeks postoperatively, and the dog exhibited a gradual improvement in motor function. At 10 weeks postoperatively, the dog showed no neurological deficit including knuckling but the tarsal joint hyperextension did not improve due to ankylosis. The dog had undergone tarsal arthrodesis and exhibited almost normal limb function without any neurologic sequela until the last follow-up at 2.5 years postoperatively.